What is the number of macrophages in the human body?

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Request for Question Clarification by knowledge_seeker-ga on 13 Aug 2003 08:05 PDT

Do you mean the number of types of macrophages, or the actual number
of macrophage cells in the whole body?

-K~

Hello danen,

According to data from Wintrobe's Clinical Hematology, Ninth Edition,
edited by G.R. Lee, T.C. Bithell, J. Foerster, J.W. Athens, J.N.
Lukens and published by Lea & Febiger, Philadelphia PA, 1993, which is
cited by Robert A. Freitas Jr in Nanomedicine, Volume I: Basic
Capabilities, published by Landes Bioscience, Georgetown, TX, 1999:

there are approximately "0.2 trillion macrophages and other
reticuloendothelial (mononuclear phagocyte) cells throughout the human
tissues"

Freitas also gives a total white blood cell count of 0.4 trillion in
the blood. Monocytes, which are precursors of macrophages, make up
approximately 2-8% of that total, ie about 8-32 billion monocytes in
total. Their numbers will vary with the general status of health.

The Freitas figures for numbers of different cells in the body are
available online: http://www.nanomedicine.com/NMI/8.5.1.htm

The "other reticuloendothelial (mononuclear phagocyte) cells" will
include cells that resemble macrophages and have similar functions,
such as the Kupfer cells in the liver.

Search strategy: total macrophages "in the human body"

I hope this is the information that you are seeking.

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Clarification of Answer by tehuti-ga on 13 Aug 2003 09:28 PDT

I forgot to cite a reference for monocytes making up 2-8% of the total
white blood cell count:

" Monocytes normally make up 2-8% of the WBCs (100-500/mm3 of blood).
   a. Monocytes are important phagocytes.
   b. Monocytes differentiate into macrophages when they leave the
blood and enter the tissue. Macrophages and dendritic cells are very
important in phagocytosis and serve as antigen-presenting cells in the
adaptive immune responses"
From: IV. THE INNATE IMMUNE SYSTEM E. CELLS INVOLVED IN BODY DEFENSE 
    1. Defense Cells in the Blood: The Leukocytes
By Gary Kaiser, Community College of Baltimore County
http://www.cat.cc.md.us/courses/bio141/lecguide/unit2/innate/bloodcells.html

Blood Breakdown..
plasma matrix = 55%
rbc's +wbc's = 45%

Erythrocytes (Red blood cells) 4.4-5.5 million mer mm^3

Leukocytes (White blood cells) 5,000-10,000 per mm^3, Neutrophils
60-70% total Leukocyte count (act as phagocytes in the body tissues),
Eosinophils 2-4% total Leukocyte count (kill internal parasites and
detoxification of basophilic bi-products), Basophils 1% total
Leukocyte count (Non-specific Inflammatory response), Lymphocytes
25-30% total leukocyte count (Specific immune response), Monocytes 5%
total leukocyte count (become phagocytic macrophages of connective
tissue at injury sites)